POLAND SAYS DETAINEES MAY FACE FORMAL CHARGES

By JOHN DARNTON, Special to the New York Times

Published: March 9, 1982

WARSAW, March 8—
Polish Government officials said today that some of the 4,000 detainees under martial law could be placed on trial. At a news conference called by Justice Minister Sylwester Zawadzki, the officials said that an amnesty decree issued before the imposition of martial law Dec. 13 did not cover all offenses.

''The amnesty act covers a wide range, but not all offenses under Polish penal law,'' said Mr. Zawadzki. ''It is possible to conduct penal proceedings.''

An example of an activity that may lead to prosecution, he said, is ''the question of creating an illegal political party.'' The officials said that, of the 6,000 people originally detained, ''maybe a hundred'' had already been formally arrested and would face charges.

Until now, Government officials have said that, except for a handful of cases in which criminal charges had already been brought or in which investigations were under way before Dec. 13, people who were detained did not have to fear legal prosecution. Pressure for Emigration Seen

The new interpretation raises the possibility that the authorities may threaten detained people with trials to persuade them to accept the recent offer of emigration. The offer is designed to remove what the authorities regard as troublesome elements.

According to Roman Catholic Church sources, state security officials have told the families of some detainees that formal charges may be brought if the emigration offer is not heeded.

The authorities are evidently trying to facilitate emigration procedures. In one detention camp, application forms have been passed out.

A Western embassy has had 15 applications for visas from detainees who have been freed. ''Two of them said they were told it was either leave the country or be sent to Siberia,'' the ambassador said. Union sources have said for weeks that at least 18 union officials are being held in isolation at Bialoleka Prison on the northern outskirts of Warsaw. No Confirmation on Walesa

Mr. Zawadzki said Lech Walesa, the union leader, was being detained in isolation. Asked whether he would be granted permission to attend the baptism of his new daughter, Mr. Zawadzki said that, from time to time, home visits were permitted for compassionate reasons. Whether this could apply to christening, he could not say.

The officials said at today's news conference that there were now 3,953 people in detention in 25 camps. Hipolit Starszak, head of the investigations bureau of the Ministry of the Interior, said that, from Dec. 13 to March 1, 1,650 people had gone on trial for crimes committed under martial law.

Of those, he said, 486 involved political offenses such as organizing strikes and handing out leaflets. The others were apparently charged with minor violations such as breaking curfew. Forty people were acquitted.

Last week a Catholic priest was arrested in connection with the killing of a policeman on a streetcar in broad daylight. The press reported that a revolver said to have been used in the killing was found in the parish home of the priest, identified only as ''Sylwester Z.'' Suspects are generally not identified in Poland until sentence is passed.

Two other men accused of actually carrying out the killing were also apprehended, according to a spokesman for the Interior Ministry. They were residents of Grodzisk Mazowiecki, southwest of Warsaw. The official announcement said that ''the two acted in an organized gang of several people.''

The authorities have said that the policeman, Sgt. Zdzislaw Karos, was shot in cold blood by two men who jumped on the streetcar and then escaped in a red Polish Fiat. Unofficial versions assert that the policeman was intoxicated, became involved in a brawl with passengers and was shot with his own gun during a tussle.

The announcement of the priest's arrest came only a few hours after the Government press agency disclosed that another priest had been sentenced to three and a half years' imprisonment on a charge of ''slandering Poland's system and its authorities.''

The charge against the priest, the Rev. B. Jewulski, stems from a sermon he delivered on Dec. 20, one week after martial law was imposed. It was the first known instance in which a priest has been sentenced to prison under martial law. ---- Pope Thanks American People Special to the New York Times

ROME, March 8 - Pope John Paul II today thanked the American people for their ''expressions of solidarity and practical help'' to the Polish people.

Addressing a Congressional group headed by Representative David R. Obey, Democrat of Wisconsin, which has just visited Poland, the Pope suggested that the legislators tell Congress about the Polish people's needs.

His remarks, made public by the Vatican, made no mention of the United States Government. The Pope has voiced disagreement with President Reagan's sanctions against Poland for the imposition of martial law.